Many parents want to find schools where their children will thrive. But for parents of children with disabilities, the stakes of finding a good school cannot be higher.

Parents’ concerns range from whether a school will have the right services and supports to help their child advance academically, to whether the school can keep their child physically safe. In some cases, having that information, which is not publicly accessible and often obtained through directly contacting school officials or participating in school tours, can be lifesaving. But discrimination can prevent families from gaining such crucial knowledge.

I faced this situation while researching a possible move from Chicago to New York. A major part of the decision was finding appropriate schooling options for our able-bodied son and physically disabled daughter. Scheduling tours of schools in both cities for my son was easy but proved tricky for my daughter. When I mentioned her disabilities in email or phone requests, far fewer schools replied to me. When they did, they often declined a tour, telling me that they did not give tours as policy (even when I knew other parents that had successfully toured) or would provide a tour only after I purchased a home in their catchment zone.

One administrator even told me over the phone, “You can come tour our program if you look through the eyes of your (able-bodied) son. But not if you look through the eyes of your (disabled) daughter.”

As a sociologist who studies discrimination, I was intrigued by these differences. So, I called my longtime co-author András Tilcsik and suggested we put this experience to a broader test. Was this experience unique, or were public school principals steering families with disabled children away from their neighborhoods?

We conducted an audit study of more than 20,000 K-12 public schools in four states. We emailed school principals, telling them that we were moving to the area and researching schools for our child. We asked if we could set up a school tour. Half of the emails indicated that the child had a disability, signaled with an individualized education plan (IEP); the other half did not. Because disability intersects with other identities, we also varied the perceived gender of the child and the race of the parent.

We found that principals were indeed significantly less likely to grant tour requests when they believed the child was disabled versus nondisabled. Most principals did not outright say no. They simply chose not to respond. We conducted a follow-up experiment of 578 principals to understand factors motivating this behavior. It turns out principals viewed disabled students as imposing a greater financial and temporal burden on their schools. Potentially to preserve resources, they engaged in a subtle form of exclusion: strategic avoidance.

While stereotypes and stigma surrounding disability undoubtedly play a role in the continuing marginalization of disabled children and their families, perceived resource constraints are also at the heart of disability discrimination in U.S. schools. When Congress passed the Individuals with Disabilities in Education Act, it mandated that public school districts must educate disabled students no matter how extensive or costly their support needs. To offset the expense of doing so, Congress set a goal of funding 40% of the cost of special education.

But Congress has never come close to meeting this goal, leaving states and school districts to bear the bulk of the cost of special education. In a context of decreasing public school funding and rising numbers of children identified as having a disability — 15% of all public school students receive special education services — school officials are put in an impossible situation in which they may feel they have to choose between meeting the needs of their disabled versus nondisabled students.

Some school districts have responded to this predicament by trying to limit the number of enrolled students who qualify as disabled. For example, Chicago Public Schools intentionally delayed or denied special education evaluations and services to thousands of children, 2018 reporting showed.

Others, like the Michigan school district at the heart of a March Supreme Court ruling, refuse to provide students with supports they need to progress academically and that are required by federal law. Many districts engage in targeted efforts to remove students with high support needs from their classrooms and conserve school resources, such as using isolation rooms, formal suspensions, expulsions or secret, informal school removals.

What can policymakers do to create a more inclusive landscape that discourages local school officials from isolating, removing, or ignoring disabled students or their families? Fully funding special education at 40% is an important start.

Lauren Rivera is a professor of management and organizations at Northwestern University’s Kellogg School of Management. Her research focuses on gatekeeping and inequality in education and employment. She is the author of the award-winning book “Pedigree: How Elite Students Get Elite Jobs.”